Although various testing means have been developed to determine the strength of fluorescent lights and/or the starters associated therewith, the majority of these devices have been either for checking the equipment at the factory before shipment or for testing the same at the retail outlet prior to sale. A few devices have been developed for testing lamps or the combination of lamps and starters in the field but invariably these have required the lamps to be removed from their sockets or the test device to at least be in some way connected into the electrical system of the light.
Whenever large numbers of fluorescent lights are being maintained, it is impractical to check each light on an individual basis as required by the testers presently available and thus the lights usually are allowed to hum or burn out. Once a large enough group of the lights have given trouble, then it is worthwhile to go back and replace them all at once. This procedure is not only costly in wasted energy but also greatly reduces the peak lumen output of the system.